Speed-varying mechanism.



N0. 680,9l6. Patented Aug. 20, IQOI. W. S. HALSEY.

SPEED VARYING MECHANISM. (Applicafion filed Sept. 22, 1899.)

(No Model.) 2 Sheets-Sheet l Uhlllllli Starts a'rnrtr rrrcni WVILLIAM S.IIALSEY, OF PITTSBUBG, PENNSYLVANIA.

SPEED=VARYBNG ECHANlSli/l.

SPECIFICATION forming part of Letters Patent No. 680,916, dated August20, 1901.

Application filed $eptember 22,1899. Serial No. 731,270. (No model.)

To all whom it may concern: I

Be it known that 1, WILLIAM S. HALSEY, of Pittsburg, in the county ofAllegheny and State of Pennsylvania, have invented a certain new anduseful Improvement in Speed- Varying Mechanism, of which improvement thefollowing is a specification.

The objectof my invention is to provide a simple and effective mechanismwhereby the rotative speed of a driven shaft may be varied as desiredrelatively to that of a driving-shaft which rotates at a uniformdetermined rate of speed.

To this end my invention, generally stated, consists in the combinationof a driving-shaft, a driven shaft, a drivingwheel mounted loosely onthe driving shaft, a driven wheel rotatable with and movablelongitudinally on the driven shaft in contact with the driving wheel,helical inclines through which rotative pressure is imposed upon thedriving-wheel, and means for moving the driven wheel relatively to theaxis of the driving-shaft.

The improvement claimed is hereinafter fully set forth.

In the accompanying drawings, Figure 1 is a side view in elevation of aspeed varying mechanism, illustrating an application of my invention;Fig. 2,a transverse section through the same on the line 00 w of Fig. 3;Fig. 3, a vertical central section; Fig. 4:, an end view, on an enlargedscale, of the driving collar; and Fig. 5, a side view of the same and ofthe adjacent portion of the hub of the drivingwheel.

In the practice of my invention I provide a supporting frame or bed 1,having suitable bearings 2, in which a main or driving shaft 3 ismounted. The drivingshaft is in this instance shown as carrying adriving-pulley P, to which rotation at a uniform determined speed isimparted by a belt passing around a pulley which is rotated by anysuitable prime mover. It will, however, be obvious that thedriving-motor may, if desired, be directly connected to thedriving-shaft 3.

A frictional driving-wheel 5,which is shown as of conical form, ismounted loosely on the driving-shaft, and the end thrust of said shaftis taken upon an adjustable set-screw 6, engaging a thread in the frame1, the point of said set-screw bearing on a washer 8, to which the endthrust of the driving-shaft is transmitted through a spring 7, fittingin an end recess therein.

A collar et is fixed upon the driving shaft adjoining the end of the hubof the driving- Wheel 5, which is nearer the larger diameter thereof,and the adjacent faces of the collar and hubare each provided withahelical incline 4 5*, respectively, said inclines corresponding indirection and pitch on the two members, so that when abutting underpressure they will constitute continuous drivingsurfaces. Where, as inthe instance illustrated, the driving-shaft is to be adapted to rotatethe driven shaft in either direction, the collar and driving-wheel hubmust each be provided with helical inclines of alternately oppositeinclination, as shown in Figs. 4 and 5; but if rotation in one directiononly is desired the inclines lead onlyin one direction, the abuttingfaces of the two members being formedin the manner of a clutch orsaw-tooth coupling.

A driven shaft or counter-shaft 9 is mounted in bearings 10 on theframe, said shaft carryinga frictional driven wheel 12, which is fittedon a longitudinal key or feather 11. The inclination of the driven shaftand the diameter of the wheel 12 are such that'the periphery of saidwheel shall always be in contact with an equal length of the peripheryof the driving-wheel 5 in order that the former may be rotatable by thelatter in any and all positions within its range of traverse upon thefeather 11. The end thrust of the driven shaft is taken upon a set-screw13, and it carries a bevel-gear 14 or a pulley, if preferred, throughwhich its movement may be transmitted to the shaft which is to befinally rotated or the mechanism or device which is to be actuated. Thedriven wheel 12 is moved longitudinally upon the feather 11, andconsequently toward or from the axis of the driving-shaft, in accordancewith the direction of its movement, by a shifting-lever 15, pivoted by apin 16 to the frame and carrying studs or projections 17, one or theother of which when the lever is moved upon its pivotal axis bearsagainst the adjacent side of the driven wheel 12 and moves the same onits feather correspondingly with and proportionately to the directionand range of traverse of the shifting-lever 15.

In the operation of the mechanism when the driving-shaft 3 is'rotated ineither direction the pressure of one of the helical inclines of thecollar 4- against the adjacent helical incline of the hub of thedriving-wheel 5 would if unopposed move said wheel longitudinally on thedriving-shaft in the direction of its smaller diameter; but suchmovement being resisted and prevented by the contact of the wheel 12with the driving-wheel 5 the latter is pressed against the former withsuch force as to compel the wheel 5 to rotate with the driving-shaft andby its frictional contact with the wheel 12 to rotate the same and thedriven shaft 9, on which it is mounted. The angle of the line of contactof the peripheries of the driving and driven wheels with the axial lineof the driving-wheel not being varied by longitudinal movement of thedriven wheel on the shaft 9, such movement consequently does not effecteither increase or diminution of the constant resistance imposed by thedriven wheel to the longitudinal movement of the driving-wheel, whichmovement is therefore impossible, regardless of the condition of rest ormotion or the direction of motion of the driven wheel. For the samereason the resistance to the longitudinal movement of the driven wheelwhen such movement is desired is that due to the frictional contact ofthe driving-wheel and is uniform throughout and in either direction oflongitudinal movement of the driven wheel. The speed of the driven shaftwill of course be greater or less accordingly as the wheel 12 is broughtnearer to or moved farther from the larger diameter of the driving-wheel5 by appropriate movement of the shifting-lever 15 in one or the otherdirection.

My invention presents in practice a substantial advantage overconstructions embodying a driving-wheel which is fixed to the shaft inthe particular that the degree of frictional driving contact of thedriving and driven wheels is variable by and directly proportionate tovariations in the resistance imposed upon or power required to betransmitted by the driven shaft. The driving and driven wheels aretherefore under all conditions maintained in contact only with thatdegree of force which is normal and necessary to effect the rotation ofthe driven shaft for any determined resistanceor load and Without beingsubject to the undue and unnecessary wear which would result if theywere invariably engaged with the frictional contact required to effectrotation of the driven shaft under the maximum resistance or load forwhich it is adapted.

It will be obvious to those skilled in the art to which my inventionrelates that the structural details thereof may be materially variedfrom those of the example illustrated without departure from thegoverning principle and leading features of my invention. Thus, forexample, the driving-Wheel might be a disk instead of a cone and thedriven wheel be traversed toward and from its axial line transverselythereto instead of at an angle therewith, as in the instance shown.Other structural variations embodying the same essential operativeprinciple can readily occur to the skilled constructor, and I do nottherefore limit myself to the specific construction which is hereindescribed and shown.

I claim as my invention and desire to secure by Letters Patent 1. In aspeed-varying mechanism, the combination of a driving-shaft, a drivenshaft, a driving-wheel mounted loosely on the drivingshaft, a drivenWheel rotatable with and movable longitudinally on the driven shaft, incontact with the driving-wheel, means for imposing rotative pressureupon the drivingwheel through the contact of helical inclines, and meansfor moving the driven wheel relatively to the axis of the driving-shaft.

2. In a speed-varying mechanism, the combination of a driving-shaft, africtional driv= ing-wheel mounted loosely thereon, a driven shaft, africtional driven wheel, rotatable therewith and movable thereon incontact with the driving-Wheel, a pressure-imposing device comprisinghelical inclines on the driving-Wheel and on an abutting member fixed tothe driving-shaft, and means for moving the driven wheel toward and fromthe axis of the driving-shaft.

3. In a speed-varying mechanism, the combination of a driving-shaft, africtional driving-wheel mounted loosely thereon, a collar fixed on thedriving-shaft and provided with a helical incline adapted to abutagainsta corresponding incline on the driving-wheel, a driven shaft, africtional driven wheel rotatable therewith and movable thereon incontact with the driving-wheel, and means for moving the driven wheeltoward and from the axis of the driving-shaft.

4:. In a speed-varying mechanism, the com bination of a driving-shaft, aconical frictional driving-wheel mounted loosely thereon and having ahelical incline on one end of its hub, a collar fixed to thedriving-shaft, and having a helical incline adapted to abut against thatof the driving-wheel, a driven shaft journaled at an angle with thedriving-shaft, a frictional driven wheel fitted to traverse on alongitudinal feather on the driven shaft and having its periphery incontact with that of the driving-wheel, and a pivoted shifting-lever foreffecting the longitudinal movement of the driven wheel.

WILLIAM S. I-IALSEY. Witnesses:

J. SNOWDEN BELL, CLARENCE A. WILLIAMS.

